SUMMARY Pathogenic microorganisms encounter a variety of environmental stresses following infection of their respective hosts. Mycobacterium tuberculosis , the etiological agent of tuberculosis, is an unusual bacterial pathogen in that it is able to establish lifelong infections in individuals within granulomatous lesions that are formed following a productive immune response. Adaptation to this highly dynamic environment is thought to be mediated primarily through transcriptional reprogramming initiated in response to recognition of stimuli, including low-oxygen tension, nutrient depletion, reactive oxygen and nitrogen species, altered pH, toxic lipid moieties, cell wall/cell membrane-perturbing agents, and other environmental cues. To survive continued exposure to these potentially adverse factors, M. tuberculosis encodes a variety of regulatory factors, including 11 complete two-component signal transduction systems (TCSSs) and several orphaned response regulators (RRs) and sensor kinases (SKs). This report reviews our current knowledge of the TCSSs present in M. tuberculosis . In particular, we discuss the biochemical and functional characteristics of individual RRs and SKs, the environmental stimuli regulating their activation, the regulons controlled by the various TCSSs, and the known or postulated role(s) of individual TCSSs in the context of M. tuberculosis physiology and/or pathogenesis.

The LIFE+ Project PM 3 : Particulate Monitoring, Modeling, Management is coordinated by the Department of Labour Inspection in Cyprus and funded in part by LIFE+ Environment Policy & Governance. The project aims at the analysis of dust emissions, transport, and control options for Cyprus, as well as at the identification of "natural" contributions (Directive 2008/50/EC). The ultimate objective is to provide inputs for the design of a dust management plan to improve compliance to EC Directives and minimise impacts to human health and environment. This paper presents a short analysis of historical monitoring data and their patterns as well as a description of a dynamic dust entrainment model. The pyrogenic PM 10 emissions combined with the wind driven emissions, are subject to a two phase non-linear multi-criteria emission control optimization procedure. The resulting emission scenarios with an hourly resolution provide input to the Comprehensive Air quality Model with extensions (CAMx) 3D fate and transport model, implemented for the 4,800 km master domain and embedded subdomains (270 km around the island of Cyprus and embedded smaller city domains of up to 30 km down to street canyon modeling). The models test the feasibility of candidate emission control solutions over a range of weather conditions. Model generated patterns of local emissions and long-range transport are discussed compared with the monitoring data, remote sensing (MODIS derived AOT), and the chemical analysis of dust samples.